如何使用postgres数据库,Docker和Kubernetes来保存数据？

Question

我正在尝试在我的容器上安装一个永久磁盘,该容器运行Postgres自定义映像.我正在使用Kubernetes并遵循本教程.

这是我的db_pod.yaml档案:

apiVersion: v1
kind: Pod
metadata:
  name: lp-db
  labels:
    name: lp-db
spec:
  containers:
    - image: my_username/my-db
      name: my-db
      ports:
        - containerPort: 5432
          name: my-db
      volumeMounts:
        - name: pg-data
          mountPath: /var/lib/postgresql/data
  volumes:
    - name: pg-data
      gcePersistentDisk:
        pdName: my-db-disk
        fsType: ext4

我使用命令创建磁盘gcloud compute disks create --size 200GB my-db-disk.

但是,当我运行pod时,删除它,然后再次运行它(就像在教程中一样)我的数据不会持久化.

我尝试了这个文件的多个版本,包括PersistentVolumes和PersistentVolumeClaims,我尝试更改mountPath,但没有成功.

编辑

用于创建Postgres图像的Dockerfile:

FROM ubuntu:trusty
RUN rm /bin/sh && \
    ln -s /bin/bash /bin/sh

# Get Postgres
RUN echo "deb http://apt.postgresql.org/pub/repos/apt/ trusty-pgdg main" >> /etc/apt/sources.list.d/pgdg.list
RUN apt-get update && \
    apt-get install -y wget
RUN wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -

# Install virtualenv (will be needed later)
RUN apt-get update && \
    apt-get install -y \
        libjpeg-dev \
        libpq-dev \
        postgresql-9.4 \
        python-dev \
        python-pip \
        python-virtualenv \
        strace \
        supervisor


# Grab gosu for easy step-down from root
RUN gpg --keyserver pool.sks-keyservers.net --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4
RUN apt-get update && apt-get install -y --no-install-recommends ca-certificates wget && rm -rf /var/lib/apt/lists/* \
    && wget -O /usr/local/bin/gosu "https://github.com/tianon/gosu/releases/download/1.2/gosu-$(dpkg --print-architecture)" \
    && wget -O /usr/local/bin/gosu.asc "https://github.com/tianon/gosu/releases/download/1.2/gosu-$(dpkg --print-architecture).asc" \
    && gpg --verify /usr/local/bin/gosu.asc \
    && rm /usr/local/bin/gosu.asc \
    && chmod +x /usr/local/bin/gosu \
    && apt-get purge -y --auto-remove ca-certificates wget

# make the "en_US.UTF-8" locale so postgres will be utf-8 enabled by default
RUN apt-get update && apt-get install -y locales && rm -rf /var/lib/apt/lists/* \
    && localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8
ENV LANG en_US.utf8

# Adjust PostgreSQL configuration so that remote connections to the database are possible.
RUN echo "host all  all    0.0.0.0/0  md5" >> /etc/postgresql/9.4/main/pg_hba.conf

# And add ``listen_addresses`` to ``/etc/postgresql/9.4/main/postgresql.conf``
RUN echo "listen_addresses='*'" >> /etc/postgresql/9.4/main/postgresql.conf
RUN echo "log_directory='/var/log/postgresql'" >> /etc/postgresql/9.4/main/postgresql.conf

# Add all code from the project and all config files
WORKDIR /home/projects/my-project
COPY . .

# Add VOLUMEs to allow backup of config, logs and databases
ENV PGDATA /var/lib/postgresql/data
VOLUME /var/lib/postgresql/data

# Expose an entrypoint and a port
RUN chmod +x scripts/sh/*
EXPOSE 5432
ENTRYPOINT ["scripts/sh/entrypoint-postgres.sh"]

和入口点脚本:

echo " I am " && gosu postgres whoami

gosu postgres /etc/init.d/postgresql start && echo 'Started postgres'
gosu postgres psql --command "CREATE USER myuser WITH SUPERUSER PASSWORD 'mypassword';"  && echo 'Created user'
gosu postgres createdb -O myuser mydb && echo 'Created db'

# This just keeps the container alive.
tail -F /var/log/postgresql/postgresql-9.4-main.log

Answer 1

最后,似乎真正的问题是我试图从我的入口点脚本创建数据库.诸如创建数据库或用户之类的事情应该在容器创建时完成,所以我最终使用标准的Postgres映像,这实际上提供了一种创建用户和数据库的简单方法.

这是Postgres的全功能配置文件.

apiVersion: v1
kind: Pod
metadata:
  name: postgres
  labels:
    name: postgres
spec:
  containers:
    - name: postgres
      image: postgres
      env:
        - name: PGDATA
          value: /var/lib/postgresql/data/pgdata
        - name: POSTGRES_USER
          value: myuser
        - name: POSTGRES_PASSWORD
          value: mypassword
        - name: POSTGRES_DB
          value: mydb
      ports:
        - containerPort: 5432
      volumeMounts:
        - mountPath: /var/lib/postgresql/data
          name: pg-data
  volumes:
    - name: pg-data
      persistentVolumeClaim:
        claimName: pg-data-claim

感谢所有帮助过我的人:)